Drafting machine



21, 1937. L. McDb AL 2,102,636

DRAFTING MACHINE v I Filed Aug. 15, 1932 4 Sheets-Sheet 1 -4 Sheets-Sheet '5'- (6E II II I 1 Dec. 21, 1937. L.. MCDONALD DRAFTING MACHINE Filed Aug. 15, 1952 D 21,;11937. .LMCDOQ LD 4. "2,102,636

DRAFTING MACHINE IH V 259 INVIINTOR.

Patented Dec. 21, 1937 UNITED .5

eA'r'r FFICE 25 Claims.

This invention relates to drafting machines; and it has for its objects, the provision of a protractor universally movable over a drawing surface'and adapted to be held stationary at any 5 point over the drawing surface by clutches operat- 7 ing to hold the straight-edge stationary, and to hold the protractor, or carriage upon which the protractor is mounted, stationary on the straightedge, and it has clutches for holding the protractor rules or straight-edges at any angle, all

of which are operated from the carriage or protractor in the larger machines. It includes novel clutches conveniently positioned and easily operated, and spacing mechanism which may be con- I veniently used when numerous parallel equidistant lines or points are to be drawn or located, and other features herein described and claimed.

Fig. 1 is a plan View of the machine in one 5 is a section on the line II of Fig.4, and on.

the line 55 of Fig. 1. Figures 6 and 6A are views of the rule-holder clutch detached. Fig. 'l is a side elevation of the straight-edge clutch. Fig. 8 is a plan view of the same. Fig. 9 is a side elevation on the line 33 of Fig. 1, of the rule- 30 holder and lever for operating the rule-holder clutch. Fig. 10 is a side elevation of one of the carriage clutches. Fig. 11 is a section on the line 4-4 of Fig. 1. Fig. 12 is aside elevation of means for elevating the protractor straight-edges. Fig. 13 is a sectional elevation of one of the ball bearings of the carriage and of the cross head. Fig. 14 is a plan view of a second species of the machine with the protractor detached. Fig. 15 is a rear elevation of the same. Fig. 16 is a contin'uation of Fig. 15 on the line II of Fig. 14. Fig. 17 is an upper end elevation of the same. Figs. 18 and 19 are views of the carriage clutch of the species of Fig. 14. Figs. 20 and 21 are views of the spacing toggle support. Fig. 22 is a third species of the machine. Fig. 23 is an upper end elevation of the same. Fig. 24 is a rear elevation and Fig. 25 is a continuation of the same on the line II of Fig. 22. Fig. 26 is a section on the line 2-2 of Fig. 22.

Similar numerals refer to throughout the several views.

Referring to Figs. 1, 2, and 3, a guide I having its edges turned inward forming a straight-edged channel, is attached preferably to the upper edge 01' a drawing board 2 by supports 3, or to the upper similar parts edge of the type of drafting table frame adapted tohold interchangeable drawing boards. A straight guide 4 has its edges turned inward forming a straight-edged channel similar to guide I, and has a cross bar 5 attached to its upper end by elevating blocks and screws l. The cross bar has a ball bearing assembly 8 at each end which fits closely between the inturned edges of stationary guide I. The left extension of the cross bar is shown broken away in Fig. 1. The cross bar 10 is held in placeon guide I by a bar 9 attached to cross bar 5 near each end, which bars have flat bearing ends sliding on the inner side of the in: turned flanges of stationary guide 5. A carriage I0 is held in place on movable guide 4 by similar 15 bars I I and similar ball bearing assemblies I2 attached to each end, running on and closely fitting between the inturned edges of movable guide 4. A clutch (see Figs. '7 and 8) for holding the movable guide stationary on guide l, consists of a plate 20 53 having a flange I4 at one end, its opposite end having a shoulder I5. A block It is attached to plate I3 by screw ll in slot I8, which slot permits the block to be adjusted toward the flange. And

it has a pin i9, a slot 2|! in one end, and a tapered 25 bearing 2| partially on shoulder I5 and partially on the adjacent edge of the block. The block and 1 flange engage opposite sides of one edge of guide I. The slotted end of the clutch is pivoted to upturned flange 22 on guide 4 by screw 23. A rod 0 I 24 housed'in one side of guide 4 extends the length of the guide and has a tapered bearing on its upper end received by bearing 2I for adjusting the block and flange to a close contact with opposite sides of one edge of guide I. be some clearance between the inner side of guide 4 and rod 24 at its tapered end to prevent the rod holding the clutch rigid. The gripping effect of the clutch is not due solely to the wedging effect of the tapered end of the rod in the tapered bearing, which should be slight. Its gripping effectis due to the proportional width of the engaging part of the clutch to the length therefrom to pivotal screw 23, which should be about one to three or less, whereby frictional resistance due to leverage prevents sliding of the clutch, when pressure is applied to its pivoted end only. A bar 25 is pivoted to one of the elevating blocks 6, and it has a notch 26 in its free end which notch, while rod 24 is disengaged from its bearr ing 2 I, is held in engagement with pin I 9 by spring 21 which spring is connected to bar 25 and to cross bar 5, whereby gripping of the clutch is prevented and displacement of the gripping end of the clutch is prevented while the movable guide There should 35 might be sufficient friction between the clutch and the-rod on which-the clutch slides while thecarriage is being moved to return the rod to its enis being moved. A bar 28 is connected rigidly with the upper end of rod 24 by link 29and it has an inclined lower edge which depressesbar 25 out of engagement with pin I9 while rod24 is returning to its engaged position. A spring 3d has one end'attached to link 29; A member 3| is attached to guide 4 by screw 1 and has an extended end to which the opposite end of spring 33 is attached. The extended endis so positioned that when rod 24 is drawn out sufficiently the spring is moved to the opposite side of its bearing on member 3| which change of position of the spring reverses the direction of its force, thereby hold-- ing the rod out. The means for actuating rod 24 for operating the clutch just described, from the" carriage, consists of a clutch 32 (see Fig; 11) which has a hole receiving rod 24 loosely, and has an outward extension for manual operation, and an inward extension, and. grips opposite sides of rod 24 at points obliquely across the rod from one point of contact to the'other by, forward pressure on itsoutward' extension, and by rearward pres-' sure on its inward extension, the degree of the gripping being proportional to the pressure applied to either of its extending ends longitudinally of rod 24. The clutch slides loosely on rod 24.

in its straight nongripping positionin which positioniitg is heldatthe rear extremity of its movement: against two stop pins 33 oncarriage Ill by spring attached to its inwardly extending end between the pins, the other end of spring being: attached to the downwardly extended end of pin' 35' so as to be more nearly in line with the outwardly extended-end of the clutch. 'When the clutch is pressed into engagement with rod 24 by the'finger of the operatonand the clutch and rod are move'dforward, the outer end of the clutch contacts first with the outer end of member 36 which is one ofthe' carriageclutch members, a

slightfurther movement brings the inwardly extended end of the clutch into contact with pin 35 while pressureof a finger of the operator on clutch 32 between its contacts with pin 35 and its contact withv the outer end of clutch 36, holds the clutch in its nongripping position at the forward extremity of its movement, permittingcarriage- It to be movedlongitudinally on its guide. When the clutch is released spring 34 causes the clutch to griprod 24 and return it. One object of arrangr ing' spring 30 to reverse-the direction of its force by-outward movement of rod 24 whereby the rod is held in its disengaged position,'is,that there gage'd position, especially in the horizontal position of guide 4, in which case the rod would not be held-out by its weight.

The clutch for holding carriage ll] fast on movable guide 4, consists of two clutch members 36 and 31, each having aflange 33 (see Fig. 10) the opposite ends of which flanges form shoulders which are held in engagement with the edges of the channel of guide 4 at points obliquely thereacross from one point of contactof the shoulders to the other, by arched spring 39a connected with holes in flanges 38. tending ends for manual operation. They are heldin pla'ce'between the under side of the carriage and the-upperside of theguide, and by two pins 39 on carriage l3 contacting withthe outer edges of their inner ends, the: clutch members being reversed with respect to each other, whereby one member prevents movement of the carriage in one direction longitudinally of theguide, and the They have outwardly ex- 7 7 other member prevents movement of the carriage in the opposite direction by their, contact with pins which'movement is limited by their contacting with pins 46 on the carriage. Pins 46 are notentirely essential. The clutch members may also be arranged to be disengaged by moving their outer ends from each other, in which case pins 39 should contact with the inner edges of their inner ends 7 instead of their outeredges.

The carriage clutch and the clutch of the movable guide may be operated independently of each other, or they may be operated simultaneously by moving the extended ends of clutchmembers 32 and 31' toward each other, bywhich movement the end of clutch member 32 will contact with member 36, releasing it and permitting the carriage'to be moved in any direction over the drawing surface. 7 V V Spacing mechanism for the movable guide consists of a graduated'edge 4! on cross bar 5, a stop d2 having a. slot engaging and sliding .on'the graduated edge of the: cross bar, extending over the adjacent edge of guide I, and having'an inclined' surface 43' on its extension, and a screw v44 for holding it at any point along the graduated edge. A support 45 having a slot engaging opposite sides of the adjacent edge of guide I, and

held in place by the edge of cross bar 5, has a pointed toggle 46 pivotally mounted on its upper part. The toggle has an extending arm 41. A

spring 48 has one-end attached tocross bar andits other end extending downward against the lower'edge of support 45 for sliding it to the stop, the point ofto-ggle striking the inclined surface of the stop and turning into contact with guide I slightly forward of its pivotal bearing,

which prevents further forward movement of the support. 'VVhen guide 4 is moved forward an extension 49' of member 3!. contacts with the upper part of support 55 bringing guide t to rest, then if thespacing mechanism is being operated from the carriage, rod 26 is released and in returnin the inclined surface of bar 28 depresses arm 41, which disengages the point of the toggle and again allowsspring A8 to move the support and toggle forward. With small machines the toggle maybe conveniently depressed directly by the finger of the operator without rod 24, and without a clutch for the movable guide, in which case a member 50 for preventing rearward movement of guide 4 while the support is being moved forward, is attached to cross bar 5 byscrew 5|, and extends over the adjacent edge of guide I, and has a spring 52 pivoted to the extension, whichcontacts with the guide at a sufiicient angle to cause it to grip against rearward movement of guide 1. The

spring may be turned to one side out ofoperative position.

Spacing mechanism for the carriage for spacing equidistant points, lines etc., comprises a tractor conveniently detachable ing the links to flanges 64.

downward movement of the lever permits the engage the edges of the channel ofv the guide on which the carriage is mounted, when pressure is applied to the outer end of the clutch, whereby it remains stationary while pressure on clutch member 36 by a finger of the operator advances the carriage until stop 54 contacts with clutch 56, thereby arresting movement of the carriage. Clutch 56 is held in place by the carriage, pin 51, and spring 59 which has one end attached to the carriage and its other end attached to the clutch which it returns to its disengaged position after each movement of the carriage. grips in the same way as clutches 36 and 31.

Two sockets 6!] on the carriage hold the proand interchangeable with lettering devices, or other devices.

The protractor comprises, a support 6| having two flanges 62, two links 53 having shanks 64 engaged by sockets 60, and two screws 65 for clamp- A rule-holder 61 is pivoted on support BI by screw 68, and has two arms supporting two straight-edges 69 at right angles with respect to each, other. A graduated arc 66 is fixed to support 6I. The rule-holder has an arm I3 extending underarc 66. 'A V- clutch I4 (see Figs. 1, 4, 5, and 6) is held in place under the are by the arm of the ruleholder, its diverging ends contact with the sides of stud I5 on the end of arm I3. i The clutch has twoshoulders I6 near its diverging ends and a shoulder 11 near its opposite end, which shoulders engage opposite edges of arc 66. The clutch should be sufliciently thin to engage the arc with slight resiliency. This clutch will grip the are by pressure on one of its ends only, due to the relative positions of the contact points of the clutch with the are, but pressure on its opposite ends at the same time in the same direction will prevent its gripping, whereby 'it'may be slid on the arc, and for this purpose a lever 79 is pivoted on arm I3 of the rule-holder near its pivotal center, or it may be pivoted on a stud screw substituted for screw 68. One end of the lever is extended for sufiicient leverage for changing the angle of the rule-holder easily. A spring 8! connected with the rule-holder and the lever exerts upward pressure against the extended end of the lever. The

.opposite end of the lever is turned downward 50 and has a slot 82 (see Fig. 5) in the down turned end, the slot converging toward its lower end, its narrow lower end engaging the projecting'end 14a. of clutch I4 when the slotted end of the lever is up, the slot and the lower sides of end I la of the clutch being inclined inward for sufiicient clearance when the slotted end of the lever is down, as there must then be no connection between the lever and the clutch. Downward movement of the extended end of the lever about one eighth of an inch connects the slotted end of the lever with the extended end of the clutch, then side pressure on the same end of the lever changes the angle of the rule-holder.

For convenient setting to the most frequently used angles which are multiples of 15 degrees, a

series of holes in support I are spaced 15 degrees apart, and a pin 84 (see Fig. 4) slidable in a hole in I9 and in a bushing 85 in arm I3, is held at its lowest position in its bearings by spring 86 attached to the lever and to the pin. In the highest position of lever I9 the pin cannot enter,

This clutch clutch to become efiectlve.

Means for elevating the protractor and its straight-edges relative to the drawing surface for preventing blotting by contact with freshly inked lines, comprises a bar 8? (see Fig. 12) having its ends turned to a sufficient angle for engaging opposite sides of a straight-edge, a fiat spring 88' to be onthe under side of thestraight-edges, having one of its ends engaged in a slot 89 in one end of the bar, and a screw 90 in the opposite end of the bar having a reduced end engaging a hole in the opposite end of the spring, whereby the spring may be arched for raising the straightedges. The bars are slidable on the straightedges. The protractor is raised to correspond with the straight-edges by loosening the thumb nuts on screws 65.

Fig. 14 is a second species of the machine, in which a guide I52 having its edges turned inward forming a straight-edged channel, is attached to a drawing board, or table. straight-edged guide I53 has a roller I54 attached to it near its upper end by bolt I55, the lower end of the bolt forming a tape-red bearing for the roller. The roller runs on the edges of the channel of guide I52, and there is a close fit between the same. Two bars 556 attached to the under side of extensions I57 of the movable guide by screws I58, have slots I59 in each end. engaging sisting of two clutch members I65 having flanges i IIiIla forming shoulders spaced to contact with the opposite edges of the channel of guide I52 obliquely thereacross from one point of contact of the shoulders to the other. Two pins I6I on the movable guide contact with the outer edges of the lower ends of the clutches, and a spring I62 holds their shoulders in engagement with the edges of the channel. They are set reversed with respect to each other to prevent movement of guide I53 in either direction longitudinally of guide I52. Their frictional resistance to pressure applied to their lower ends through pins IGI by pressure against the movable guide, is proportional to the pressure, and is due to the relative positions of their contact points with opposite edges of guide I52, whereby a sort of toggle action is obtained in which the frictional resistance is greater than the pressure applied to the movable guide. They are disengaged from the guide by moving their upper ends towards each other,

which movement is limited by their contacting with two pins I63. They may, however, be set to be releasable by moving their upper ends from each other. Pins 5 63 are desirable butnot essential. A carriage I 64 is mounted on movable guide I53 by rollers I65 attached to the carriage by screws I66 having tapered lower ends for bearings for the rollers. The upper ends of clutch members I66 may be operated directly with small machines, but are preferably operated from the carriage with all sizes. For this purpose, two bell crank levers I61 and I68 are pivoted on the movable guide by pins I69 and lit, the ends of two of their arms being connected to the outer sides of the upper ends of clutch members I66, their other two arms being connected to each other end to end, whereby a reverse movement of the levers with respect to each other is'obtained giving a reversemovement to the clutch members,

moving their free ends towardeach other when they are set as shown. A wheel 'I'II having a grooved periphery is pivoted to the other end of lever I61. 7 side of carriage I64 by screw I13, a cord I14 has one of its ends attached to a downwardextension I75 of lever I12, and runs over wheel I'TI and grooved wheel I16 pivoted on the under side of the-lower 'end of guidel53, and its other end is attached to the carriage. An extension Ill on the carriage is a convenient finger hold when moving lever in toward it for disengaging the clutch of the movable guide.

The clutch IItl for holding the carriage fast on guide I53 is shown in Figs. 18 and l9,and is a plate having a deep slot H9 formed in' one end across from edge to edge of the plate, for engaging with slight resiliency opposite sides ofguide has a screw I93 in itsupper end pivotally engage ingthe short slot of the clutch, the axis of the pivoting screw being at right angles tothe face ofthe clutch. The proportional width of the engaging slot of the clutch to the length of the clutch from its engaging slot to the screw in the slotin its opposite end should be about one'to three, or less, whereby the frictional resistance of the clutch to pressure applied-through the carria'ge to the pivotally attached end of the clutch, due to leverage, will be greater than the pressure and thereby prevent sliding of the clutch, but means holding the gripping end of the clutch rigid with the carriage will permit the clutch to slide on guide I53 which means consists of a lever I84 pivoted to the under side of the carriage, which lever extends for manual operation and 40 has an arm extending under the carriage, the arm 184 toward extension I'E'I. Actuation of said lever I84 will move V-point l35 into engagement with notch I86, whereby pressure on the carriage longitudinally of the guide will move the carriage and slide the clutch on the guide. engaging slot of the clutch on the guide is necessary, but it should not be so close as to prevent easy sliding of the carriage when the clutch is held rigid with the carriage as described.

Spacing mechanism for the carriage, comprises, va graduated edge I88 on the carriage, a stop l89 -having a slot engaging the graduated edge of the carriage, held adjustable thereaiong by screw I99, and having an inclined front edge I9l which extends slightly under the carriage. A support I92 (see Figs. 20 and 21) has a slot 93 across its face at one end, not so deep as the slot of clutch I78, for engaging and sliding on the. graduated edge of the carriage, held in place by a rib I94 sliding in a groove on the under side of the edge of the carriage. arranged to engage and slide on the adjacent edge of guide I53, as support'45. Atoggle I95 is pivoted on the upper end ofthe support by screw I96. A spring l9'I under the carriage having one end ,attached to the carriage and its other end ex-' ment of the supportwhile the carriage is being A lever I12 is pivoted on the under of Fig. 1, received by the sockets.

A spring I81 normally holds 7 A close fit of the This support may also be forward a pin I98 on angle I8I' contacts with the upper part of support I92 which brings thec'arriage to rest, whereat lever I 84 is released and extension I99 of the lever strikes an arm. 200' of the toggle and raises its point sufliciently for it to go forward again. The carriage has sockets for holding a protractor having shanks like that This spacing mechanism is useful for spacing lines and points, and it is useful for spacing letters when a lettering devicehaving shanks received by the'sockets is used interchangeably with the protractor.

The means for maintaining guide I53 at right angles to guide;I52 for movement longitudinally on guide I52, consists of a cord 202 extending lengthwise of guide I53 and over wheels 203 and 284 and having its ends attached respectively to the upper left corner and to the lower right corner of a drawing board, and a cord 285 extending lengthwise of guide I53 and over grooved wheels 295 and 251 andhaving its ends attached respectively to the upper right corner andto the lower left corner of the drawing board.

'Any of the usual cord and pulley means attached to a drawing board for maintaining parallelism of the straight-edge, may be used in place of a cross bar having one, or having two rollers on each end cooperating with a guide.

A third species of the machine is shown in Figs. 24, 25, 26, 27 and 28, in which a straight guide 235 having its two edges turned inward forming a straight-edged channel, is attached preferably to the upper edge of a drawing board, or table. A straight guide 239, which is the same as guide 235, has an extension 231 of its bottom part. at its upper end. A cross bar 238', shown 'broken away on the right, is attached to guide 238 by bolt 239 and screw 248, clamping raising blocks 24! between them.' The cross bar has a roller 242 at each end fitting closely between and running on the side edges of the channel of the stationary guide, and a bar 243 near each end slides on the inner side of the inturned flanges of guide 235 for holding the cross bar on the guide. A carriage 244 has a roller 245 at each end running on the edges of the channel of the movable guide, and fitting closely between them. Two bars 249 attached to'the under side of the carriage by screws 24?, hold the carriage on guide 235. The carriage has two sockets for detachably holding a protractor having shanks like the shanks oi protractor of Fig. 1.

The clutch for holding the carriage fast on the 7 arm 253 of one of the toggles and to a right angled extension of the other toggle, whereby, moving the extended end of either toggle toward the other releases the points of both toggles. The end of link 252 in arm 253 extends upward and contacts with extension'25il when the outer ends 7 of toggles 249 are moved toward each other, which;

limits their movement towardeach other.

The clutch for holding the movable guide fast' on the stationary guide, comprises, two toggles 254 and 255 pivoted on cross bar 238 by pivots 256, reversed with respect'to each other to prevent movement of guide 236 in either direction longitudinally of the stationary guide. Toggle 255 has an arm having a socket in its end. Toggle 254 has an arm the end of which is engaged by v the socket, whereby, the movement of one moves the other in the reverse direction on its bearings. These two toggles may have extended ends for operation directly with small machines, but are preferably operated from the carriage with all sizes, for which toggle 255 has an arm 258 which extends a little beyond rod 259 in one side of the movable guide, the ends of which rod extend at right angles through a slot 260 in the under side of the movable guide-and connects with a hole in the arm near its end. A spring 26| has one end engaging a hole in the end of arm 258 and its other end attached to a flange on stud 262 in position for holding the toggles engaged, or for holding them disengaged when the arm is moved sufficiently far out. It is not essential thatthe points of these toggles be sharp,

The means for operating the clutch from the carriage, consists of a clutch 263 (see Fig. 28)

havinga hole in it receiving rod 259 loosely, and

the carriage to be moved longitudinally on the movable guide. A cross bar 264 fixed in a slot in the under side of the clutch, has an inclined surface 265 at its rear end, and an inclined surface 266 at its forward end. When pressure on the outer end of the clutch forces it into engage ment with the rod, in a slightly inclined position, and the clutch and rod are moved forward, the inclined surfaces of the cross bar of the clutch contact with one of the pins 263a. and with pin 261, which causes a slight'reverse turn of the clutch to its straight disengaged position. A projection 268 forming a fork brings the clutch to rest against pin 26?. The spring 26! holds the rod out while the carriage is moved on the guide.

When the clutch is released a spring 269 attached to the carriage and to the inwardly extending part of the clutch, causes the clutch to grip the rod and return it, the clutch being brought to rest against pins 263a.

Cross bar 238 has a graduated edge and a stop 216 like that of Fig. 1, and a support 21! having a slot engaging opposite sides of the stationary guide on one of its edges, slidable thereon, held in place by the adjacent edge of cross bar 238, and'having a toggle 212 pivoted on it, like the toggle of the spacing mechanism of the carriage of Fig. 14,-having a downwardly extended arm 212, and toggle 255 has an upwardly extended arm 214 which contacts with arm 2l3 while rod 259 is returning to its rearward position, and thereby, disengages the point of the toggle from the guide. Spring 215 having one end attached to cross bar 238 and its other end turned downward against the lower edge of support 2'! I, moves the support forward when the point of the toggle is raised.

The machines herein described have holding means on their carriages for holding lettering devices, or protractors, interchangeable with each other for use of the machines as lettering machines, or as drafting machines. The preferred arrangement of the movable guide with respect to the stationary guide is at right angles. However it is obvious that in the combinations herein claimed that include the stationary guide and the movable guide, the angular position of the movable guide could vary a number of degrees from its preferred right angle position, and the machines would still be useful as drafting machines, or as lettering machines.

I claim:

1. A straight guide adapted to be attached to supporting means having a drawing surface, a straight guide and means adapting it to be guided by said stationary guide, longitudinally thereof, and for maintaining it at right angles thereto, a carriage having means engaging said movable guide for guidance of the carriage longitudinally thereon, a protractor carried by said carriage, having a rule and means supporting the rule for angular adjustment with respect to said movable guide, a clutch carried by said movable guide adapted to engage said stationary guide for holding the movable guide fast thereon, means connected with said clutch extending lengthwise of said movable guide and for disengaging the clutch from the stationary guide, and means on said carriage, the manual operation of which, actuates said lengthwise extending means, permitting the carriage to be moved in any direction over the drawing surface.

2. A straight guide adapted to be attached to supporting means having a drawing surface, a straight guide and means adapting it to be guided by said stationary guide,longitudinally thereof, and for maintaining it at right angles thereto, a carriage having means engaging said movable guide for guidance of the carriage longitudinally thereon, a protractor carried by said carriage,

having a rule and means supporting the rule for angular adjustment with respect to said movable guide, a clutch carried by said carriage adapted to engage said movable guide for preventing movement of the carriage longitudinally thereon, a clutch carried by said movable guide adapted to engage said stationary guide for holding the movable guide stationary, means connected with the clutch of the movable guide extending lengthwise of the movable guide, and means carried by said carriage, the manual operation of which, disengages the carriage clutch and actuates said lengthwise extending means for disengaging the clutch of the movable guide practically simultaneously with the disengagement of the carriage clutch, permitting the carriage to be moved in any direction over the drawing surface, and for disengaging said clutches independently of each other for movement of the carriage in two directions at right angles with respect to each other.

3. A straight guide adapted tobe attached to supporting means having a drawing surface, a straight guide and means adapting it to be guided by said stationary guide, longitudinally thereof, and for maintaining it at right angles thereto, a, carriage having means engaging said movable guide for guidance of the carriage longitudinally thereon, a protractor carried by said carriage, having a rule and means supporting the rule for angular adjustment with respect to said movable guide, a clutch carried by said movable guide for holding the movable guide fast on the stationary guide, means connected with said clutch extending lengthwise of the movable guide, and for operating the clutch, and means on said carriage, the manual operation of which actuates said lengthwise extending means, said operating means permitting the carriage tobe moved in any direction over the drawing surface, when the clutch is disengaged.

4. A straight guide'adap'ted to be attached to supporting means having a drawing surface, a

' straight guide and means adapting it to be guided and means adapting it to be guided by said staby said stationary guide, longitudinally thereof, and for maintaining it at right angles thereto, a carriage and means adapting it to be guided by said movable guide longitudinally thereof, a protractor carried by said carriage, having a rule and means for supporting the rule for angular adjustment with respect to said movable guide, a clutch carried by said carriage for holding the carriage fast on the movable guide, spacing mechanism carried by said movable guide cooperating with said stationary guide for horizontal spacing, means connected with said spacing mechanism, extending lengthwise of said movable guide and for operating said spacing mechanism, and means carried by said carriage, the

manual operation of which, actuates said lengthwise extending means.

5. In mechanism of the class described, a clutch, comprising, aplate having across its face at one end, a flange extending at right angles to its face, and a shoulder near its opposite end, a block and means attaching it to the face of said plate so as to make it slightly movable toward said flange, the block and flange forming engaging jaws, pivotal attaching means at the-opposite end of the plate, the pivotal axis being at right angles to the face of the plate, a tapered bearing partially on said shoulder and partially on the adjacent edge of said block, and a rod having a tapered end received by said tapered bearings for adjustings'aid block toward said flange.

6. A stationary straight guide, a straight guide tionary guide longitudinally thereof, and for maintaining it at right angles thereto, a carriage adapted to be guided bysaid'movable guide longitudinally thereon, a clutch carried by said movable guide adapted to engage said stationary guide forrholding said movable guide stationary, a rod connected with said clutch for operating it, extending lengthwise of said movable-guide, a clutch carried by said carriage, slidable on said rod and having one end extending outwardly for manual operation and its other end extending inwardly beyond the opposite side of said rod, adapted to grip opposite sides of the rod at points obliquely stop pins, against which stop pin the rod-engaging clutch is held'by said spring inits disengaged position, and to which position it is returned by said spring after each forward movement of the rod, returning the rod also. g

e 7. In mechanism as in claim 6, an outwardly extending member carried by said carriage in position-to contact with the outwardly extended end of said rod-engaging clutch, and a pin carried by said carriage in position to contact with the inwardly extended 'endof the rod-engaging clutch on forward movement of the clutch, whereby the clutch is forced to its disengaged position against said pin and member at, the forward extremity ofits'movement by a finger of the operator press ing on the clutch at a point between its points of contact with said pin and member.

8. A stationary straight guide, a-straight guide and means adapting it;to be guided by said stationary guide, longitudinally thereof, and for maintaining'it at right angles thereto, a carriage adapted to be guided by said movable guide longitudinally thereof,.spacing mechanism carried by -said movable guide cooperating with said stationary guide for horizontal spacing, when the movable guide is arranged in the vertical position, a rod connected with said spacing mechanism for operating it, extending lengthwise of said movable guide, a clutch carried by said carriage slidable on said rod, having one end extending outward for manual operation, and itsother end extending inwardly beyond the opposite side of said rod, adapted to grip opposite sides of the rod at points obliquely across the rod from one point of contact to the other by forward pressure on its outwardly extended end, or by rearward pressure on its inwardly extended end, and adapted to be disengaged by a slightreverse movement, two stop pins on said carriage, a spring having one end attached to said carriage, and its other end attached to said inwardly extended part of the clutch at a'point between said stop pins, against which stop pins the clutch is held by said spring in its disengaged position at the rear extremity of its movement, and to which position it is returned by said spring after each movement of the rod,

returning the rod also.

longitudinally thereon, a clutch carried by said movable-guide for holding the movable guide fast on the stationary guide,-a rod connected with said clutch extending lengthwise of the movable guide and for operating the clutch, a clutch carried by said carriage slidable on said rod, having one end extending outwardly for manual operation, and its other end extending inwardly, adapted to grip opposite sides of said rod at points obliquely across the rod from one point of contact to the other by forward pressure on its outwardly extended end, or by rearward pressure on its inwardly extended end, and to be disengaged by turning it slightly the reverse, two stop pins on said carriage, a spring having one end attached to said carriage and its other .end attached to said inwardly extended part of the rod-engaging clutch between said stop pins, against which stop pins the rod-engaging clutch is held by said spring 'in' its disengaged position at the rear extremity of, its movement, a bar fixed to the rod-engaging clutch extending parallel with the rod and having an inclined surface at each end, and two pins, including one 7 of the first mentioned pins, on said carriage spaced to contact with said inclined surfaces by forward movement of the clutch and rod, thereby giving the clutch a slight reverse turn, releasing its grip on said rod at the forward extremity of its movement. I

10. A straight guide, a member adapted to be guided by said guide, longitudinally thereof, spacing mechanism: for said guided member, comprising, a graduated edge on said guided member, a stop having means holding it adjustable long said graduated edge, the stop extending ing over the adjacent edgeof said guide, and having an inclined surface on said extension, a support and means holding it slidable on the adjacent sides of said guide, a pointed toggle pivoted on the upper part of said support, a spring 'means mounting it for movement longitudinally having one end attached to said guided member and its other end engaging the lower part of said support, sliding it to said stop, the point of the toggle striking the inclined surface of said stop and turning into contact with said guide a short distance forward of the pivotal bearing of the toggle, thereby holding the support stationary, an extension on said guided member, which when the guided member is moved forward contacts with the upper part of said support, bringing the guided member to rest, means for disengaging the point of said toggle, whereby the sup" port is again moved forward by said spring, and means for preventing rearward movement of said guided member while said support is being moved forward.

11. A straight guide, a member adapted to be guided by said guide, longitudinally thereof,

spacing mechanism carried by said guided member, comprising, a graduated edge on the guided member, a stophaving means holding it adjustable along said graduated edge, and having an inclined edge extending over the adjacent edge of said guide, a support having a slot engaging opposite sides of said guided member on its graduated edge, slidable thereon, a pointed toggle pivoted on the upper part of said support, the pawl having an extended arm, a spring having one of its ends attached to said guided member and its other end engaging the lower part of said support, for sliding the support to said stop, the point of thetoggle striking said inclined surface ofthe stop and turning into contact with said guide a short distance forward of the pivotal bearing of the toggle, thereby holding the support stationary, a projection on said guided 3 member, which when the guided member is moved forward contacts with the upper part of said support, arresting the movement of the guided member, a clutch carried by said guided -member for holding it fast on said guide, means for disengaging said clutch, and means operated 'by said disengaging means while it is returning to its normal position, for raising the'point of the toggle out of contact with said guide, whereby the support is moved forward by said spring.

12. A straight guide, a member adapted to be guided by said guide longitudinally thereof, spacing mechanism carried by said guided member, comprising, a graduated edge on the guided member, a stop having means holding it'adjustable along said graduated edge, and having'an inclined edge extending over the adjacent edge of said guide, a support having a slot engaging opposite sides of said guided member on its graduated edge, a pointed toggle pivoted on the upper part of said support, a spring having one of its ends attached to said guided member, and its other end engaging the lower part of said support, for sliding the support to saidstop, the

point of the toggle striking said inclined surface of the stop and turning into contact with said guide a short distance forward of the pivotal bearing of the toggle, thereby holding the support stationary, a projection on said guided member, which when the guided member is moved forward contacts with the upper part of said support, arresting the movement of the guided member, means for disengaging the point' of said toggle, whereby the support is again moved forward by said spring, and means for preventing rearward movement of said guided member while the support is being moved forward by said spring.

13. A channeled guide, a carriage having on said guide, a clutch carried by said carriage for holding it fast on said guide, and means for disengaging the clutch, spacing mechanism carried by said carriage, comprising, a graduated edge on said carriagaa stop having means holding it adjustable along said graduated edge, a spacing clutch having two shoulders spaced to contact with the opposite side edges of the channel of said guide at points obliquely across the channel from one point of contact of said shoul ders to the other, a spring having one of its ends attached to said carriage and its other end attach ed to said spacing clutch, two stops on said carriage against which the spacing clutch is held by said spring in its disengaged position until pressure on its outwardly extended end, by the operator, 1 moves it into engagement with said channeled guide, where it remains stationary while pressure on said disengaging means of the first mentioned clutch, by the operator, disengages it and advances the carriage until the stop on said graduated edge contacts with the spacing clutch.

14. A channeled guide, a member having means mounting it for movement longitudinally on said guide, spacing mechanism carried by said guided member, comprising, a graduated edge on said guided member, a stop having means holding it adjustable along said graduated edge, a spacing clutch having two shoulders spaced to contact with the opposite side edges of the channel of said guide at points obliquely across the channel from one point of contact of said shoulders to the other,

a spring having one of its end attached to said 1 guided member and its other end attached to said spacing clutch, two stops on said guided member against which the spacing clutch is held by said spring in its disengaged position, means for moving the spacing clutch into engagement with said channeled guide where it remains stationary while the guided member is advanced until the stop on said graduated edge contacts with the spacing clutch, after which the spacing clutch is released, and means for preventing rearward movement of said guided member while said spring slides said spacing clutch to its disengaged position against said two stops.

15. A channeled guide, a member adapted to be guided by said channeled guide longitudinally thereof, a clutch carried by said guided member for holding it fast on said channeled guide, consisting of a pair of similar clutch members each having two shoulders, means for holding the shoulders of each clutch member in contact with the respective opposite side edges of the channel of said guide at points obliquely across said channel from one point of contact of said shoulders to the other, means flexibly connecting one end of each clutch member with said guided member, the clutch members being substantially reversed with respect to'each other, whereby, one clutch member prevents movement of said guided memher in one direction longitudinally of said channeled guide, and the other clutch member pre- ,posite edges of said are with slight resiliency, a

stud on said rule-holder with the sides of which ;the inner sides of the diverging ends of said clutch contact, whereby the frictional resistance {of said clutch holds the rule-holder stationary, means on said rule-holder for engaging the opposite end of said clutch holding it rigid with the rule-holder thereby preventinggripping of the clutch, for sliding it on the are for changing the angle of the ruleeholder and rule. V

17. A straight guide, a member adapted to be guided by said guide, for movement longitudinally thereof, a clutch for holding said guided member fast on said guide, comprising, a body portion having a slot across it closely engaging opposite sidesof said guide, means pivotally attaching one end of said clutch to said guided member, the pivotal axis being at right angles to the plane of said slot, the proportional length of said engaging slot to the distance fromsaid slot to the pivotal bearing of the clutch being such as togive the required leverage to prevent sliding of the clutch on said guide by pressure against its pivotal end in, either direction longitudinally of 'the guide, and means carried by said guided member adapted to engage said clutch near its gripping end, holding the clutch rigid with the guided member, thereby preventing said leverage action, the operation of which means, permitting the guided member to be, moved longitudinally of the-guide. 18; A straight guide, a member adapted to be guided by said guide, longitudinally thereof, a clutch for holding said guided member fast on ,said guide, comprising, a body portion having one end formed into a deep transverse slot closely engaging with slight resiliency opposite sides of said guide the depth of saidslot and the thicknessofthematerial forming said slot being proportioned for obtaining said slight resiliency the slot not engaging its full depth with said guide, means pivotally attaching the opposite end of said clutch to said guided member, the pivotal axis being at right angles to the plane of said slot, the proportional length of the engaging slot to the dis- =tance from the engaging slot 'to the pivotal bearing of the clutch being such as to give the required leverage to prevent sliding of the clutch on the guide by pressure against the pivotal end of the clutch in-either direction longitudinally 'of the guide, and means carried by said guided member adapted to engage said clutch near its gripping end, holding the clutch rigid with the guided member, thereby preventing said leverage action, the operation of which means, permitting the guided member to be moved longitudinally of the guide.

19. A stationary guide, a guide and means adapting it to be guided by said stationary. guide,

longitudinally thereof, and for maintainingit at right'angles thereto, a carriage having means cooperating with said movable guide, for guidance of the carriage longitudinally thereon, a clutch having means for operating it, carried by said movable guide for-holding the movable guide fast on the stationary guide, a wheel and means r0- tatably securing it to the operating means of said clutch, a wheel and means rotatably securing it to the lower end of, said movable guide, a cord running over the peripheries of saidwheels, having one end attached to said carriage, and a member carried by said carriage, adapted for a to and fro movement, to' which member the other end of the cord is attached, and by the operation of *of its two diverging ends, and a shoulder near its opposite end, the shoulders engaging'the opwhich member said clutch is operated from the carriage.

20., A stationary guide, a guide and means" adapting it to be guided by said stationaryguide,

longitudinally thereof, and for maintaining :it at right angles thereto, a carriage adapted .tobe

guided by said movable guide, longitudinally thereof, a clutch, consisting of two pointed toggles pivotally mounted on said movable guide in-position for their points to contact with said sta tionary guide obliquely from their pivotal centers, for toggle action, mounted substantially reversed with respect to each other to prevent movement of the movable'guide'in either direction longitudinally of the stationary guide, means holding their points in engagement with the stationary guide and means operated from said carriage, for

disengaging-the clutch from saidstationary guide.

'21. A guide, a member adapted to be guided by said guide, for movement longitudinally thereof, "a clutch carried by said guided member for holding the guided member fast on said guide, comprising two pointed toggles pivotally mounted on said guided member in position for their pointsto ,con-' tact with said guide obliquely from their pivotal centers for toggle action, mounted substantially reversed with respect to each other to normally prevent movement of said'guided memberin either direction longitudinally of the guide, aspring for holding their points'in contact with said guide,and means for releasing the points thereof from contact withsaid guide, whereby the guided member may be moved longitudinally of the guide.

22. A guide, a member having means engaging said guide for guidance of the member longitudinally of the guide, a clutch, comprising-two pointed toggles pivotally mounted on said guided member in position for their points to contact with the guide obliquely from theirpivotal centers, for toggle action, mounted substantiallyreversed with respect to each other to prevent movement of'said guidedmember in either direction longitudinally of the-guide a'rspring connected with the toggles holding-their points contact with said guide, and a linkage between said toggles, whereby movement of one toggle moves the other toggie for disengaging their points from said guide. Y r

23. Aguide, a member adapted to be guided by said guide longitudinally thereof, a clutch for holding the guided member fast on said guide;

comprising, two pointed toggles pivotally mounted on said guided member in position for the points thereof to contact'with said guideobliquely from the pivotal centers of the toggles, 'ior'toggle ction, mounted substantially reversed with respect to each other, to prevent movement of the guided memberin either direction longitudinally of the guide, each toggle having an arm, said arms being connected with each other end to end, whereby movement of one moves the other in the reverse direction, means for holding the points of said toggle in contact with said guidepand means for disengaging the points therefrom for movement of the guided member longitudinally of the guide. b

24. Aguide, a member adapted to'be guided by said guide, longitudinally thereof, a clutch for holding, the guided member fast on said guide, comprising, two pointed toggles pivotally mounted on said guided member, in position for their points to contact with said guide obliquely from the pivotal centers of the toggles, for toggle action, the toggles being mounted substantially 'reversed with respect :to each other, to prevent movement of the guided member in either direction longitudinally of the guide, and a spring holding the points of said toggles normally disengaged.

25. A guide, a member adapted to be guided by said guide longitudinally thereof, a clutch for holding the guided member fast on said guide, means for operating said clutch, a spring having one end operatively connected with said operating means and its other end pivoted to said guided member in position to direct its force toward one side of its pivotal bearing for holding the clutch engaged at one extremity of the movement of said operating means, and for directing its force toward the opposite side of its pivotal bearing for holding the clutch disengaged at the other extremity of the movement of said operating means.

LEONARD MCDONALD. 

